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Biometric personal identification system based on iris analysis

DC
  • US 5,291,560 A
  • Filed: 07/15/1991
  • Issued: 03/01/1994
  • Est. Priority Date: 07/15/1991
  • Status: Expired due to Term
First Claim
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1. A method for uniquely identifying a particular human being by biometric analysis of the iris of the eye, comprising the following steps:

  • acquiring an image of an eye of the human to be identified;

    isolating and defining the iris of the eye within the image, wherein said isolating and defining step includes the steps of;

    defining a circular pupillary boundary between the iris and pupil portions of the image;

    defining another circular boundary between the iris and sclera portions of the image, using arcs that are not necessarily concentric with the pupillary boundary;

    establishing a polar coordinate system on the isolated iris image, the origin of the coordinate system being the center of the circular pupillary boundary, wherein the radial coordinate is measured as a percentage of the distance between the said circular pupillary boundary and said circular boundary between the iris and sclera; and

    defining a plurality of annular analysis bands within the iris image;

    analyzing the iris to generate a presenting iris code;

    comparing said presenting code with a previously generated reference iris code to generate a measure of similarity between said presenting iris code and said reference code;

    converting said similarity measure into a decision that said iris codes either do or do not arise from the same iris; and

    calculating a confidence level for the decision.

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